In vitro studies on antifungal activity of tea (Camellia sinensis) and coffee (Coffea arabica) against wood-rotting fungi

The present study reports the sensitivity of ten different wood-rotting fungi towards eight samples of tea and two samples of coffee. The tea samples included five CTC black teas, one orthodox black tea and two green teas. The different fungi tested were sensitive to different tea and coffee samples to variable levels. Green tea caused the maximum growth inhibition and it was 100% in case of Phanerochaete chrysosporium and Sporotrichum pulverulentum. Of the black tea samples, orthodox black tea was more effective inhibitor for all the fungi tested. Phlebia radiata was the most sensitive fungus to all the black tea samples except Lipton Cheers. The growth of Daldinia concentrica was least affected by all the black tea samples. The two coffee samples showed better inhibition than CTC black tea samples. The inhibitory effect of tea and coffee extracts was greatly reduced on their filtration. All the tea and coffee samples tested showed more than 50% reduction in their inhibitory activity. The inhibitory effect was completely lost in spent black tea leaves. The antifungal effect of pure caffeine was tested at different concentrations. Majority of the fungi were totally inhibited at a concentration of 0.3% whereas, D. concentrica, P. radiata and P. palustris showed complete inhibition at a concentration of 0.5 percent.